This invention relates to fireplaces and more particularly to a fireplace which vents directly into the room in which it is installed to heat the room and has a construction which permits use of larger log sets and is less expensive to produce than prior art constructions.
Gas burning log sets having artificial logs which are either placed within an unvented fireplace or an unvented fireplace insert are today very popular since the burning gas supplies a very high heat level, e.g., in the order of 40,000 BTU, efficiently. Since substantially all of the gas is burned cleanly, the burning efficiency is very high and the carbon monoxide and carbon dioxide generated do not exceed acceptable limits. Oxygen depletion safety devices are provided to ensure this. Thus, the combustion products need not be vented outside the building and may be directed into the room to heat the room and may additionally heat adjacent rooms. The fireplace in which the burning log set is installed may be a conventional wood burning fireplace with the exhaust flue closed and, of course, the wood support grate removed and replaced by the log set. In other instances the fireplace may be specifically designed for use with a gas burning log set. In the prior art such fireplaces have been constructed in the same manner as direct vent fireplaces, i.e., those where the combustion products, generally from wood, are vented to the exterior of the building. These fireplaces therefore have multiple spaced apart sheet metal walls welded or otherwise connected together. One such fireplace of this type is illustrated in Moon et al U.S. Pat. No. 5,054,468. The multiple wall construction limits the actual log receiving space for fireplaces of given outside dimensions since the space between such walls causes a reduction in the width of the log receiving space. Additionally, fireplaces with this construction have a relatively expensive manufacturing cost, for various reasons, not the least of which is the amount of sheet metal required and the necessity of connecting the various walls together, the latter generally being done by welding.